The Rams came out in their "hands" alignment as they were expecting an onside kick, which is why Austin was the lone deep man. He also only got 8 yards because there were no blockers (everyone was up around 10 yards from the kick to try and recover the onside kick) and he slid on the play. He did that to both avoid injury, and because the Rams were up by a ridiculous amount of points that they just wanted to Run out the clock as much as possible, rather than get great field position.
That's a plausible explanation, but with a league leading 6 drops, I'm not sure Austin qualifies for the "hands" alignment. I guess it's a a good thing he was playing deep.:D